Defects in complex intermetallics and quasicrystals

In crystals with large unit cells, conventional plasticity mechanisms involving dislocations as carriers of plastic deformation tend to fail due to the occurrence of unfavorably large Burgers vectors or energetically costly stacking faults. In this paper, we discuss the structure of defects in a number of structurally complex alloy phases possessing large cell parameters. We show that different mechanisms to accommodate dislocations apply, ranging from rather conventional scenarios to highly exotic mechanisms involving completely novel types of defect.